Payments add modal form

* adds modal form for adding payments
* generalizes generic_table_form.html for table-form-like usage in modal_form.html
* adds css enhancements for focused input fields
* adds BaseModalForm as specification to BaseForm, which inherits the BSModalForm class as well
* adds translations

intervention/views.py

@@ -4,7 +4,7 @@ from django.utils.translation import gettext_lazy as _
 from django.http import HttpRequest
 from django.shortcuts import render, get_object_or_404
 
-from intervention.forms import NewInterventionForm, EditInterventionForm, OpenInterventionForm
+from intervention.forms import NewInterventionForm, EditInterventionForm
 from intervention.models import Intervention
 from intervention.tables import InterventionTable
 from konova.contexts import BaseContext